package com.chatroom.service;

import com.chatroom.model.User;

import java.util.List;
import java.util.Optional;
import java.util.Set;

public interface UserService {
    User registerUser(String username, String password);
    Optional<User> findByUsername(String username);
    Optional<User> findById(Long id);
    boolean validateUser(String username, String password);
    List<User> getAllUsers();
    void addFriend(User user, User friend);
    Set<User> getFriends(User user);
    boolean existsByUsername(String username);
} 